10 Essential Discoveries in Science

Scientific developments are usually incremental. Step by step, knowledge is built upon, sometimes in a tough battle against superstition and the common consensus. But occasionally, a breakthrough is made that radically changes the playing field, as a sudden discovery allows a scientific field to flourish. Following is a list of 10 such moments in history, some seminal, a few lesser known.

10. Uranus

On the night of March 13, 1781, William Herschel turned his reflecting telescope toward the constellation Taurus and discovered a fuzzy star that he first took to be a comet. Further observations on successive evenings pinned down the planetary nature of this new object. Herschel became an astronomical superstar. Thankfully, his suggested name of “George” — after his benefactor, King George III — for the planet we now know as Uranus didn’t stick. This discovery was a fundamental breakthrough, as at the time, no one even speculated there could be more planets. For example, Galileo himself missed the chance to discover Neptune during a close conjunction with Jupiter in 1612.

9. Lithium

One of modern history’s most unsung discoveries is the use of lithium to treat manic depression. In 1949, Australian researcher John Cade wondered what would happen if he injected guinea pigs with lithium salts. To his surprise, they became extremely placid and lethargic. He then tried the same dosage with one of the asylum’s most disturbed patients, and to his surprise, the man was able to be discharged and lead a productive life weeks later. Lithium is still used today to treat psychiatric disorders, and probably would have gone totally unnoticed had it not been for the deductive assumptions of Mr. Cade.

8. Nitrous Oxide

The history of early chemistry was an often messy and frightening tale. Researchers worked with little or no regard for safety, and frequently experimented on themselves with potentially deadly chemicals. Such was the case of Sir Humphry Davy and his Pneumatic Institute of the early 1800s. In the course of his experimentation, Davy nearly killed himself with carbon monoxide and chlorine, became addicted to nitrous oxide along with friend and fellow “user” poet Samuel Coleridge, and even composed poetry while “under the influence” to study the psychological effects of various gases. But these chaotic forays into chemistry led to the modern field of anesthesiology.

7. Antibiotics

On Sept. 28, 1928 pharmacologist Alexander Fleming noticed that a culture of staphylococci bacteria left in his cluttered laboratory was being destroyed by an unknown fungus. The discovery led to penicillin and a Nobel Prize in Medicine in 1945 for Fleming. Thanks to Fleming’s work, many formerly fatal diseases caused by bacteria where literally rendered impotent overnight.

6. Radioactivity

In 1896, French physicist Henri Becquerel noticed that some photographic plates left in a drawer next to a sample of potassium uranyl sulfate were already exposed and ruined. The accidental discovery was the first known observation of radioactivity. Later work by Pierre and Marie Curie would isolate new radioactive elements such as radium and polonium, which also unwittingly exposed those early researchers to the hazards caused by radiation exposure.

5. The Cosmic Microwave Background

The field of cosmology came into its own in 1965, when Arno Penzias and Robert Wilson turned a Bell Labs microwave antenna in New Jersey skyward and noticed a pervasive, omnidirectional hiss. The men were baffled, even theorizing at one point that the noise was the result of bird droppings on the antenna. They shared their dilemma with a scientist at Princeton University, who immediately realized Penzias and Wilson had discovered microwaves emanating from the edge of the universe. In effect, the men had accidentally confirmed the Big Bang Theory. Penzias and Wilson shared the 1978 Nobel Prize for Physics for their discovery.

4. Evolution

Charles Darwin’s theory of evolution resulted from his trip to South America and the Galapagos Islands in the 1830s, but his theory didn’t reach the public for more than 20 years, until the 1859 publication of On the Origin of Species. Darwin’s theory is as simple and elegant to some as it is troubling to others; Darwin himself agonized over what his theory said about natural selection. In time, however, evolutionary biologists have recognized the role teamwork and even altruism may have to play in our ultimate survival.

3. Newton’s Laws of Motion

Sir Isaac Newton was a true polymath, the rare individual who had an impact on nearly everything he studied. Among his creations were calculus, theories of light and the spectrum, and the reflecting telescope. But his greatest contribution was his three laws of motion. Today, when we send a spacecraft to a distant world, we can be assured that it will arrive at the right place at the right time, thanks to Newton.

2. The DNA Helix

It’s important to note that when Charles Darwin published On the Origin of Species, he knew nothing about the mechanism by which these “monstrosities” or mutations occurred. That would have to wait until 1953, for James D. Watson and Francis Crick’s description of the DNA double helix and the coding for the material of life. This was made possible by the X-ray crystallography work by British biophysicist Rosalind Franklin. It’s worth noting that of the major discoveries of the 20th century, quantum physics and relativity where achieved before advancements in biochemistry and DNA. It was really that tough.

1. Special & General Relativity

It’s been said that the work of Albert Einstein catapulted us ahead by about 50 years, ushering in the era of nuclear physics and quantum science. Relativity was the last great theory of classical physics; his now famous E=mc2 was but a footnote produced in one of his papers created during his landmark year of 1905. Einstein spent most of his life simply thinking about two things, the nature of light and gravity. General Relativity is a theory of gravity, while special relativity deals with inertial (or relative) frames of reference. One of the first great observational proofs of relativity was that gravity should bend light, as observed by an expedition during a total solar eclipse in 1919.

David Dickinson is a backyard astronomer, science educator and retired military veteran. He lives in Hudson, Fla., with his wife, Myscha, and their dog, Maggie. He blogs about astronomy, science and science fiction at www.astroguyz.com.